1. Field of the Invention
The invention disclosed herein relates generally to dispensing systems, and more particularly to a dispensing system for dispensing portions of a product in a tightly controlled manner which minimizes waste caused by residual product left undispensed in a container.
2. Background of the Prior Art
A wide variety of viscous fluids, including personal care products (e.g., tooth paste, shaving cream, cosmetics, and shampoo), food products (e.g., condiments, salad dressings, and the like), as well as industrial products (e.g., cleaning fluids, lubricating oils and greases) are provided in flexible containers, such as sealed plastic bags and light collapsible tubes. Even health care products, such as blood and medications, may be stored in and dispensed from a flexible or collapsible bag.
When such products are provided in bulk, it is impractical to squeeze the container by hand in order to discharge the required quantity of its contents. Numerous devices provided in the prior art have been employed to dispense the contents of such flexible containers. Many such devices mechanically squeeze the container to extrude the contents out through a dispensing outlet. Generally, such devices have provided mechanical means such as springs or ratchets to assist in extruding the fluid from a flexible or collapsible bag. Other dispensers have typically provided arrangement of a container so that the fluid may flow from the container under the influence of gravity. In the case of blood transfusions, dispensing of fluid is typically regulated by a valve whose flow rate depends upon the amount of time desired to empty the container. For example, U.S. Pat. No. 4,850,971 to Colvin discloses an infusion pump having a linear roller driven by constant force springs to extrude blood from a flexible container by rolling an end of the container on the linear roller so as to direct the fluid toward the dispensing end of the container. Flow is regulated through use of needles of varying size on the dispensing line.
U.S. Pat. No. 4,044,764 to Szabo et al. discloses a fluid infusion apparatus having a spring motor which pulls a flexible container through a pair of rollers so as to direct fluid in the container towards the dispensing end of the container. A speed control clock motor engages a portion of the carriage carrying the container so as to resist the pull of the spring motor and provide timing control for dispensing of fluid from the container.
U.S. Pat. No. 3,151,616 to Selfon discloses a transfusion apparatus in which a flexible bag containing blood, plasma, or the like is progressively flattened as a pair of rack-gear-mounted rollers travels over the bag, directing its contents towards the dispensing end of the apparatus.
For other products, the portion of product dispensed is typically regulated by limiting the amount by which the container is compressed. For example, U.S. Pat. No. 3,738,533 to Bertrand discloses a motorized collapsible tube dispenser in which a pair of motor-driven rollers are driven downwards over a vertically suspended tube so as to direct the contents of the tube towards the dispensing end.
U.S. Pat. No. 6,089,405 to Schmitt discloses a manually operable dispenser for a tube containing cream or paste (e.g., toothpaste) having a housing with an opening at its base for receiving the dispensing end of the tube, and a pair of rollers which are translated up and down in the base so as to direct material within the tube toward the dispensing end.
While these dispensers have been generally satisfactory for their intended uses, there has been found to remain a need for an apparatus to control the dispensing of fluid products from such flexible containers in order to facilitate the dispensing of fluid products in a simple and effective manner while minimizing waste of product.
The present invention provides a dispenser for fluid products stored in a flexible container, in which operation of a dispensing pump enables an extrusion assembly to squeeze the flexible container, thus continuously directing all remaining product in the container towards the dispensing end. The dispensing pump preferably removes product from the container by positive displacement action, and more preferably by peristaltic action. A preferred embodiment of the apparatus of the invention comprises a frame with an upwardly spring biased carriage configured to removably hold a flexible container that holds product to be dispensed. An extrusion assembly preferably in the form of one or more rollers is situated at the top of the frame and is positioned such that the carriage will pull the flexible container upward past such one or more rollers as product is dispensed from the container.
The portion control dispenser described herein thus enables dispensing portions of a product in a tightly controlled manner, which in turn minimizes waste caused by residual product left undispensed in a container. A frame preferably provides support for a flexible container, and includes a moveable carriage having a drive assembly, a guide assembly, and a flexible bag mount, preferably in the form of a traction bar assembly. The frame also supports an extrusion assembly, preferably in the form of one or more rollers, for directing product towards the dispensing end of the container, and a dispensing pump for dispensing a controlled portion of product from the container. Such construction enables the flexible container to remain completely closed except for its outlet so that the product remains unexposed to the atmosphere until it exits from the dispensing pump.
It is generally contemplated that the dispenser can be employed in a variety of settings such as food service stores or institutions, other commercial settings and even for personal use in homes and the like.
In other applications, it may be important that the product be prevented from contacting the air or the environment at least until the product is properly dispensed.
Regardless of the setting, it is further contemplated that the product be initially stored in a flexible or collapsible container which can then be arranged in a dispenser operable for dispensing the product from the container in a simple and effective manner to assure delivery of a satisfactory amount of the product at a controlled rate of delivery.
It is further desirable that the dispenser be capable of dispensing the material only in response to operation by a user of a dispenser device.
The various features of novelty that characterize the invention will be pointed out with particularity in the claims of this application.